Russia and Belarus launched joint military exercises on Monday to practice the combat deployment of tactical nuclear weapons, marking the first such drills since Moscow deployed its Oreshnik hypersonic ballistic missile system to Belarusian territory.

Axar.az reports, citing The Moscow Times, that the Belarusian Defense Ministry said the drills aim to test the military’s readiness to move and deploy nuclear weapons from unplanned launch sites. The exercises involve missile units and air force detachments working in coordination with the Russian army, it said.

“The primary focus will be on practicing concealment measures, long-distance movements and calculating the deployment of forces and assets,” the ministry said in a statement.

It added that the drills are a scheduled event and are “not directed against third countries and do not threaten regional security.”